Investigation of High-Capacity Ni- Based Layered Oxide Cathodes for Li-Ion Batteries

摘要

1. Phase pure LiNiO_2 was synthesized by solid state reaction, Li excess played an important role in the surface characteristics of LiNiO_2 2. Fundamental study of LiNiO_2 set out from high-quality LiNiO_2 and enabled by a suite of synchrotron techniques (XRD, hard XAS, soft XAS, and XPS) 3. H1 to H3 phase transformation observed during charges, but gradual loss of H3 features observed over repeated charges 4. Studies on Ni electronic structure revealed Ni redox within each cycle decreased over extended cycles and provided a direct evidence that underpinned the reversible capacity loss 5. CO_2 rather than O_2 gas evolution observed for LiNiO_2 even at high charge cutoff voltage.